Magnetic signal generator



Jan.2l, 1958 K. c. MATHEWS 2,820,915

MAGNTIC SIGNAL GENERATOR Filed Nov. 15, 1956 2 Shees-Sheet 1 INVENTOR.KENNIH MATIEWS Jan. 21, 1958 K. c. MATHEWS 2,820,915

MAGNETIC SIGNAL GENERATOR Filed Nov. 15, 1956 2 Sheecs-Sheet 2 INVENTOR.KENNETH C. MAHEWS United States Patent O 2,820,915 MAGNETIC SIGNALGENERATOR Kenneth C. Mathews, Waltham, Mass., assignor toMinneapolis-Honeywell Regulator Company, Minneapolis, Minn., acorporation of Delaware Application November 15, 1956, Serial No.622,366 7 Claims. (Cl. 310-168) My invention relates to magneticsignalling devices and more particularly to improved magnetic signalgenerator or magnetic pickup.

Devices of this type are well known in the art and incorporate variousphysical magnetic and electrical configurations. The present inventionis directed to an improved magnetic signal generating device whichutilizes a simplified magnetic structure incorporating preformedelectrical coils with a minimum of parts to produce an arrangement whichis economical to manufacture and maintain and yet provides a highlyaccurate compact de- Vice which may be readily incorporated ontoassociated equipment. It is therefore the objects of this invention toprovide a simplified magnetic structure in an improved magnetic signalgenerating device which is compact in design and economical tomanufacture and maintain and yet provides a high degree of accuracy.These and other objects of this invention will become apparent from thereading of the attached description together with the drawings in which:

Figure 1 is a sectional view of signal generating device,

Figure 2 is a top view of the entire device,

Figure 3 is a top view of the core assembly for the device, and

Figure 4 is a top device,

Figure 5 is a schematic diagram of the windings in the generator ofFigures 1 and 2.

As will be seen in Figures 1 and 2, the improved magnetic signalgenerating device is comprised of a plate member which is annular inform and has a recess portion 11 and a centrally located aperture 12together with suitable mounting holes 13 therein. This circular plate aswill be seen in Figure 1 is adapted to be mounted on a base member 15through a suitable means such as screws not shown. Positioned Within thecylindrical base is a core member which is cylindrical in form having anannular periphery at one extremity and a pair of pole projections 22, 23at the other extremitywhich pole projections as will be seen in Figure 3are shown as substantially 90 segments of an annulus and are uniformlyspaced apart. It has been found, however, that the zingular size of thispair of poles may be reduced from this figure. The core member 20 isadapted to be fitted in the aperture 12 in core 10 and suitably securedtherein such as by press fitting or other external means.

Mounted within the cylindrical core 20 is an energizing winding 25 whichis wound on the bobbin 26 and which is fitted into the cylindrical coremember 20 and suitably held therein such as by press fitting or othermeans. The Winding 25 is positioned adjacent the annular periphery orextremity of the core member 20 as will be seen in Figure 1. Mounted onthe pole extensions 22 of the core member are a pair of preformedwindings 27, 28 which are wound on preformed bobbins 29 and fitted overthe pole extensions and adjacent the energizing Winding 25 and a portionof the circular plate 10. The preformed an improved magnetic view of therotor assembly for the dicated at 36 which is journaled on the windingsare also adapted to be secured to the pole ex tensions 22, 23 throughsuitable means such as glue or other adhesive, or the entire coreassembly may be impregnated after incorporation of all the parts toprovide a rigid assembly. The positionng of the primary energizing coil25 and the secondary coils 2.7, 28 on the core structure defines anaperture indicated at 3'!) within which is positioned a composite rotorstructure indicated at 31. The composite rotor structure member includesa circular flange like member 32 adapted to be positioned at oneextremity of the core structure or member 20 adjacent to and overlyingor extending beyond the peripheral rim of one extremity in the annularcore structure 20. The composite structure 31 also includes asenti-circular shaped flange portion 33 integral with a cylindricalconnecting portion 34, the semi-circular flange portion 33 beingadjacent to and positioned over the opposite extremity of the coremember 20 at which the pole members 22, 23 are located. The parts of thecomposite core structure 31, namely the fianges 32, 33 and connectingportion 34, are adapted to be mounted on a shaft inbase 15 throughsuitable bearing means 40. Shaft 36 has a flanged extremity 41 With ashoulder indicated which is positioned the inner race et the bearing 4),the outer race being press fitted into or otherwise suitably secured tothe base 15. Engaging the inner race of the bearing is a shoulderportion 45 on the circular rotor flange which spaces the flange withinthe recess 11 formed between the base plate 10 and the base 15. Theconnecting portion 34, integral with the semi-circular flange 33, restsagainst the surface of the circular plate 32 and the entire arrangementis secured on the shaft by means of a ber 20 suitable screw typeconnection means 48 fitted onto a tapped portion of the shaft 36indicated at 49. Thus it will be seen that rotative movement imparted tothe shaft 36 through the flanged extremity 41 will cause rotation of theflange portions 32, 33 relative to the core member 20. The circularflange 32 will rotate adjacent the exposed annular periphery of oneextremity of the circular core member 20 and the semi-circular flangeportion 33 will rotate adjacent the pole extensions 22, 23 of the coremember.

The positioning of the energizing winding 25 Within the core member 20will upon energization direct flux through the connecting portion 34 ofthe rotor element and through the flange sections to the poleextremities 22, 23 of the core member. core member 20 will thread thesecondary windings 22, 23 and depending upon the relative positionng ofthe semicircular flange portions 33 relative to the poles more or lessof the flux will be directed through the respective poles and windingsmounted thereon. The secondary windings as indicated in Figure 5 areadapted to be connected in a series opposition relationship such as thecurrent being generated therein will be of an opposite sense and willsubtract to give an overall output across the terminals connecting theextremities of the two wind ings which varies in magnitude and phasedepending upon the relative position of the rotor with respect to thepole members 22, 23. A resistor element '55 may be connected across oneor the other of the windings 27, 28 for balancing purposes in aconventional manner to minimize the quadrature of the exciting voltage.

In operation, an input movement to the shaft will rotate the compositerotor structure 31 relative to the core memsions 22, 23 of the coremember 20 and hence the current generated through the pickup windings27, 28. The positioning of the semi-circular flange diflerentially Withrespect to the poles varies the magnetic reluctance of the magneticcircuit defined by the composite rotor strucat 42 thereon against' tovary theflux directed through the pole extenturc and the core member 20to var;y the flux flow through the respective pole extensions and hencethe flux flow into the respective pickup Windings 27, 28 mountedthereon. By reversing the polarity of thecoils '27, 28 and connectingthe same in opposition, a differcntil of the inducted voltage in thecoils:is obtained torgive a voltage signal which is variable inmagnitudeand reversible in phase with an.alternating current energization oftheprimary winding 25 depending upon the position of the rotor 33 withrespect .to the core 20.

Thesubject magnetic signal generating device utilizes a simplifiedmagnetic core structure .with compact dimensions which cuts down on theoverall physical length of the apparatus .through useof simple bobbinwound coils to facilitate production of the same. -A veryssimple andminimum number of parts:providea compact yet rugged arrangement which ishighly accurate and economical to build. Further, the arrangementpermits the corporation of the device onto other units such asgyroscopes without anysubstantial increase in dimensional requirementsof main components. It 'will be recognized that the apparatus may bemade in somewhat modified form such as utilizing radial as opposed toaxial air gaps and consequently I 'WSh to be limited only by my appendedclaims.

I claim as my i'nvntion:

1. A-magnetic signal generatingdevice comprising, a circular platehaving an opening therein, a cylindrical core Wth sector like poleextensions at one extremity thereof, said cylindrical corebeing mountedin the opening in said circularplate, a composite rotor including acircular rotor plate positioned atone extremity *of said cylindricalcore and a semi-circular plate positioned at the other extremity 'ofsaid cylindrical core adjacent said pole extensions With a connectingsection extending through the aperture in the cylindrical core, a shaftsupporting said rotor, means mounted on said plate for journaling saidshaft, a primary energizing winding positioned With said core andencircling the connection section of said composite rotor, and secondarywindings encircling the pole extensions of said cylindrical core andbeing mounted thereon.

,2. A magnetic signal generating device comprising, a base,.acylindrical core mounted on said base and having a plurality of poleextensions at one extremity thereof, a rotor member having a circularflange at one extremity and a sector like flange at the otherextremity,said rotor member being positioned Within said cylindricl core membersuch that the circuler flange atone extremity is positioned adjacent oneextremity of said cylindrical core and the sector like flange at theother extremity is positioned adjacent pole extensions of .extremitiesof said cylindrical core overlyng the same, .shaft means journaled insaid base and mounting said rotor member for rotation intosaidcylindrical core, an .energizing winding mounted on said cylindricalcore encireling said rotor member -between said flange portions, andsecondary windings positioned on pole extensionsof said cylindricalcore.

.3. A magnetic signal .generating :device comprtising, a base, acylindrical coremounted on said base and having a pair of arcuate poleextensions at one extremity thereof., a rotor member having aoylindricalflange at oneextremity overlying the one extremity of said cylindricalcore and semicircular flange .at the otherextremity overlying the pairof poles with said rotor positioned within said cylindrical core, meansmounting said rotor for rotating movement on saidbase relative to saidcore, an enexgizing winding mounted on asaid cylindrical core encirclingsaid rotor member between said flange portions, and a pair of secondarywindings mounted on said pole extensions of said core.

4. A magnetic signal generating device comprising, a base, a cylindricalcore mounted on said base and having a pair of pole extensions atoneextremity thereof, said pole extensions being approximately sectors andspaced equalt distance 'from -:one 7 another, a :rotor member having acircular flange at one extremity and a semic'irclarfflange at the .other.extremity, said rotor member being positioned withim-saidcylindricalcore withthe circular flange positioned adjacent one extremity of saidcylindrical core and the 'semi=circular flange being positionedadjacenhpole extensions, shaft=means journaled in said base and mountingsaid rotor member for rotation relative to said cylindrical core, auenergizing winding mounted on said cylindrical core encircling saidrotor member between *said"flange portions,and a pair ofsecondary'windingspitioned on pole extensions of said cylindrical core.

5. A magnetic s'ignal-generating devicecomprising, a base, a cylindricalcorernounted on said baseandhafing a pair o'f arcuate pOIe*eXtensions atoneextremityther of,a rotor member having a cylindricalportion 't (meextremity positionefl adjacent to one extremity *ofsaid cylindrical coreand -a semi-circular 'fiange at the otler extremitypositionedadjacent tothe pair -of pole extensions, means mounting-said rotor for rotatingrnovement on said base relative *to saidcore, an 'energiz'ing windingmounted on said clindrical core encircling said rotor member between itseXtremities; :and' a pair "of secondary windingsmounted on poleextensions of said core, and means mounted :on said s'haft orrotatingsaid hft.

6. A magnetic signal generating device comptising, a basemem'ber, a coremember mounted on said base member and having an annular peripheryvatone extrem ity thereof and a plurality of pole extensionsat'the otherextremity thereof covering substantilly one-half of the peripheralsurface at this extremity and be'ing uriitorm' ly spaced, a rotoradapted to 'be positioned throu gh said core member 'having a circlarflange at one extremity. and a sector like flange at the other extremitywhich are normally positioned such that the fianges are disposedadjacent the peripheral extremities of said core, means mounting saidrotor member on said base for movement relative to said core .meniber, aplurality if pickup windings positioned on said pole extensions, andmeans for generating ,a magnetic Zfield which Will :flow through saidcore member and said rotor member [including said flangeportions.

7. .A magnetic signal generating device comprising, a base member, acore member mounted on said base member and having an annular peripheryatone extrem ity thereof and 2a ;pair rof pole extensions at the otherextremity therenf covening substantially one-half of the peripheralsurface at this extremity and being uniformo ly spaced, a rotor adaptedto be positioned through said core member having a circular flange atone =extremity and a sector like -flangeat the :other extremity whichare normally positioned such that the flanges aretdis posed adjacent=the peripheral extremities of said core, means mounting said rotor:member on said base :for movement relative to said core member, a;plurality of, pickup windings positioned on said pole extensions, and

means for generating .a magnetic field which will iflow through saidcore member and said rotor member in cluding said flange portions.

No references cited.

